In this study we notified in Gabes gulf (Tunisian coasts), the presence of an indo-pacific origin specie Ruditapes philippinarum. The samples showed 89 % for the indigenous species Ruditapes decussatus and 11 % for the exotic species Ruditapes philippinarum in Gargour (south of Sfax); whereas these percentages are respectively from 21.5 % and 78.5 % to the north of this region, in El Aouabed......